Toyota 33584100.cuw Firmware: Engine Control and Shift Quality
Learn how Toyota calibration 33584100 relates to engine control and a shift-quality update for the 2010 4Runner and FJ Cruiser.
Toyota 33584100.cuw is associated with an engine control module calibration used in a shift-quality update. The engine control module manages engine operation and participates in coordinating engine output with transmission shifts. That coordination can influence how smoothly a vehicle changes gears.
What the calibration addresses
Toyota service bulletin T-SB-0166-10 lists calibration 33584100 as an updated engine control module calibration for a shift-quality concern. The revision discussed in the bulletin is intended to improve the feel of shifting in the applicable vehicles.
During a gear change, the engine and transmission must work together as load and engine speed change. Engine control software can help manage that transition. The bulletin identifies shift quality as the reason for the update, but the available record does not describe the specific software changes or the driving conditions under which the concern occurs.
Vehicles in the service bulletin
The bulletin covers the 2010 Toyota 4Runner and 2010 Toyota FJ Cruiser. Those models define the bulletin’s scope, not confirmed fitment for calibration 33584100 in every vehicle listed. The complete calibration identifier is important when distinguishing this entry from other Toyota firmware records.
The catalog filename 33584100.cuw carries the same calibration identifier. It does not include a stock or modified variant label.